Copper selenide ( Cu3Se2 and Cu2-xSe) thin films: electrochemical deposition and electrocatalytic application in quantum dot- sensitized solar cells
Copper selenide ( Cu3Se2 and Cu2-xSe) thin films: electrochemical deposition and electrocatalytic application in quantum dot- sensitized solar cells
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硒化铜（Cu3Se2 和 Cu2-xSe）薄膜：电化学沉积和电催化在量子点敏化太阳能电池中的应用
DOI：
10.1039/c8dt03791d
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发表时间：
2018
影响因子：
4
通讯作者：
Xu Jinzhang
中科院分区：
文献类型：
--
作者：
Zhou Ru;Huang Yuanzhang;Zhou Juntian;Niu Haihong;Wan Lei;Li Yuan;Xu Jun;Xu Jinzhang
在这项工作中，高结晶度硒化铜薄膜直接沉积到导电基板上通过恒电位电沉积方法。所沉积的硒化铜涉及退火诱导的从四方Cu 3Se 2到立方Cu 2 −xSe的相变。退火也导致显着的形态变化，从树枝状纳米片连接网络和分离的颗粒形状的退火（A-Cu 2-xSe）和硒化（S-Cu 2-xSe）样品，分别。硒化铜薄膜在量子点敏化太阳能电池（QDSC）中被证明可以作为有效的对电极（CE）用于电催化多硫化物电解质再生。由硒化铜CE构建的CdS/CdSe QDSC具有相当大的功率转换效率（PCE），尤其是基于A-Cu 2-xSe CE的器件的最佳值为3.89%。增强的光伏性能得益于A-Cu 2 −xSe薄膜的连接网络微结构，它提供了大量的反应位点和有效的电荷传输途径。Tafel极化表征进一步表明，与常用的Cu 2S和Pt CE相比，非化学计量的Cu 2 −xSe CE表现出更好的电化学催化活性。这项工作突出了电沉积制备高性能QDSC的有前途的硒化铜CE的巨大潜力。
In this work, high crystallinity copper selenide thin films directly deposited onto conducting substrates were obtained through a potentiostatic electrodeposition approach. The as-deposited copper selenides involve annealing induced phase transformation from tetragonal Cu3Se2 to cubic Cu2−xSe. The annealing also leads to a remarkable morphology change from dendritic nanosheets to connected networks and separated particle shapes for the annealed (A-Cu2−xSe) and selenized (S-Cu2−xSe) samples, respectively. The copper selenide thin films were demonstrated to serve as efficient counter electrodes (CEs) in quantum dot-sensitized solar cells (QDSCs) for electrocatalyzing polysulfide electrolyte regeneration. The CdS/CdSe QDSCs constructed with copper selenide CEs deliver considerable power conversion efficiencies (PCEs), especially an optimal value of 3.89% for the A-Cu2−xSe CE-based device. The enhanced photovoltaic performance benefits from the connected network microstructure of A-Cu2−xSe films which afford a large number of reaction sites and efficient charge transport pathways. The Tafel polarization characterization further indicates that, in contrast to the commonly used Cu2S and Pt CEs, the non-stoichiometric Cu2−xSe CE exhibits better electrochemical catalytic activity. This work highlights the great potential of electrodeposition for fabricating promising copper selenide CEs for high performance QDSCs.